The invention relates to wind measuring devices commonly referred to as anemometers. In particular, the present invention visually displays the change in wind velocity with respects to the apparatus.
The apparatus is a low-pressure sensing device that visually displays a low-pressure at a distance. In the preferred form, the apparatus is an anemometer that visually represents the wind speed by displacing a float.
The apparatus is an anemometer that measures wind velocity relative to the anemometer. The anemometer comprises a pressure differentiating system and a pressure indicating system. The pressure differentiating system has a low-pressure portion and a low-pressure conduit that has a first end portion and a second end portion. The first end portions is in communication with the low-pressure area of the pressure differentiating system. The pressure indicating system is defined to have a vertical axis, a first surface, a second surface, a third surface, and a float. The first surface substantially defines a first chamber that has a substantially constant cross-sectional area with respect to the vertical location along the first chamber. Located in the lower portion of the first chamber is a lower surface defining second conduit having a first portion and a second portion where the first portion is in communication with the first chamber and the second portion is in communication with the ambient air. The second surface and the third surface substantially defines a second chamber, The second end portion of the low-pressure conduit is in communication with the second chamber. The float is positioned in the first chamber above the first portion of the second conduit. A first sub chamber is defined as the portion of the first chamber that is located above the float. A second sub chamber is defined as the portion of the first chamber that is located below the float. As low-pressure develops in the low pressure area of the pressure differentiating system, a low-pressure develops in the second chamber (via the first conduit). This causes air to flow from the first chamber to the second chamber through the conduit system and air flows from the second conduit to the second sub chamber. A portion of this inflowing ambient air flows to the first sub chamber causing lift upon the float.
In the preferred form the pressure differentiating system is a Venturi that has a front portion a central portion and a rearward portion. The central portion is the low-pressure portion of the pressure differentiating system. The conduit system can be a plurality of orifices positioned vertically along the first chamber. In another form the conduit system can be a vertically extending slit extending vertically along the first chamber. A bearing system is employed to allow the Venturi to rotate in the substantially horizontal plane. The rearward portion of the Venturi supplies sufficient air drag to orientation the front portion of the Venturi to properly face the wind.
A search of the patent literature has a number of patents directed toward when measuring devices, these being the following:
U.S. Pat. No. 5,349,334 Parson, shows a roof mounted high speed wind sensor that includes a combined wind vane and scoop. The vane aligns the intake of the scoop where the wind channels through the wind scoop assembly 18 and applies pressure against piston 28, and conductive member 34 closes a switch (electrical contacts 36) to the to sound an alarm.
U.S. Pat. No. 4,896,534 Daly, shows a wind speed sensor that is intended to be mounted on the mast supporting shroud line on a sail boat. The wind sensor is provided with a fin 24 that aligns the wind meter 20. As seen in FIG. 4. There are openings 66 in the body of the sensor through where air enters. Apparently, the air is channeled vertically around the conduit that houses float 32 so as to raise float 32 to a height proportional to the wind speed. As seen in the column 5, line 60 of the detailed description of the preferred embodiments, apparently the flow of air is completed by exiting from outlets opening 88. The flow guide 72 allows an increase in cross-sectional area which of course reduces the velocity of vertical flowing air as it travels upwardly.
U.S. Pat. No. 4,467,960 Doyle, shows a venting system in which a vane 50, aligns intake 36 into the wind so that air is forced through tube 28 past exhaust gasses to provide fresh heated air to a room.
U.S. Pat. No. 4,387,629 Bolton, shows an air evacuation device 10 where the housing 12 is direct into the wind by virtue of its shape so that air entering at 18 causes a low pressure zone just after baffle 20. This causes air to draw upwardly through the vertical tube. As disclosed in column 8 starting at line 30, it appears that the purpose of invention is to prevent the roof of a house from being blown off in very high winds.
U.S. Pat. No. 3,359,795 Walsh, shows several embodiments of a wind speed measuring device in which the wind passes through a venturi and actuates a fluid pressure gauge with its pick up tube at the low pressure area of the venturi. As seen in FIG. 5, there is a venturi tube that is directed into the wind by fin 132. The other embodiments show convex surfaces arranged so that air flows therebetween. The air may come from any direction so that an alignment means is not required. As shown in FIG. 1, the convex elements 14 and 16 are omnidirectional and a anemometer 78 is provided. As seen in FIG. 4, the convex plates move toward each other under the influence of a low-pressure area therebetween. The air velocity scale 84 is calibrated to read wind speeds given a vertical displacement.
U.S. Pat. No. 2,993,374. Dwyer et al, shows a fluid speed measuring device which is intended to detect air velocity such as air flowing from an air conditioning grill. It is not readily apparent how the device works. As seen FIG. 4, air supplied through the ports 22 and the air flows through an annular gap 20 and into the inner chamber defined by float tube 11. There must be a low pressure zone above the float 13 for it to rise. However, it is not apparent in the how this low pressure zone is exactly created. The orifice 25 is open the high range number system 33H should be used.
U.S. Pat. No. 2,838,932 Dwyer, shows a roof mounted air intake tube 14. The wind vane 12 provides drag to direct the pitot tube 14 into the wind. As seen in FIG. 2, there is a vertical cross-sectional view and the rubber stopper 43 does not allow communication between ports 44 and 46. The pitot tube 14 converts the moving air into static pressure. Apparently the weather trap 20 is used to prevent fluid or debris from entering into the upper tube 26. The anemometer 50 to tax the pressure difference between portions 48 and 49 to produce an accurate measure of the wind.
The background art such as U.S. Pat. No. 4,896,534 lifts a float by adjusting the air flux by effectively increasing the cross-sectional area of air flow of the chamber the float is housed in. This requires using a chamber that is nonuniform in cross-sectional area with respects to the vertical location and the chamber.
Other methods for measuring wind velocity include creating a low-pressure in a U-shaped tube filled with fluid such as that shown in U.S. Pat. No. 3,359,795.
The prior art fails to show an anemometer with the features that are described herein. A combination of a first chamber with a constant cross-sectional area where the flow of air changes with respects to the vertical location of the first chamber. The flow is adjusted by conduit system that allows passage of air from the first chamber to the second chamber. The second chamber is in communication with a low pressure zone of a pressure differentiating device. In the preferred form the pressure differentiating device is a Venturi. In the broader scope of invention other pressure differentiating means could be employed; however, the Venturi with a bearing system indicates the direction of the wind as well as the air velocity.
One other feature of the present invention is its ability to withstand the weather. The configuration of the preferred embodiment reduces the odds of moisture entering any of the chambers. Further, the preferred form inhibits the flow of dust and debris into the chambers.
By having a constant horizontal cross-sectional area in the first chamber, the apparatus is much easier to manufacture than prior art apparatuses that employ and increasing cross-sectional area in a chamber. Further, by employing a constant cross-sectional area in the first chamber it is easy to scale the apparatus. The first chamber could have a vertical height of a few inches or be as high as 30 feet or more.
In the preferred form the first chamber is defined by a transparent cylindrical tubing that is commonly available in a variety of diameters and lengths. To adjust the air flow within the chamber, a by conduit system is provided to the second chamber. The availability of transparent cylindrical tubing eases manufacturing of the anemometer and allows to produce a variety of heights and widths of the anemometer.